We have some high clouds moving up in the southwest flow aloft well in advance of the storm system in the middle of the country. We will probably have a mixture of sunshine and high clouds today (some thicker and some thin). Clouds will increase and thicken up later early tonight. The action of the warmer, moist air trying to move in can result in spotty light rain/ a few showers very late tonight and tomorrow. Amounts through tomorrow will remain light with most places less than 0.10 of an inch. So while looking murky, not a lot of rain. A warm frontal wave of low pressure will probably develop to the south in the Atlantic tomorrow and could help enhance some rain late tomorrow into tomorrow night, but our thinking is that that will be aimed more toward eastern New England and we are left with spotty showers/occasional light rain/drizzle and areas of fog tomorrow night and into Monday morning.
We think the developing wave of low pressure farther to our west will bring a steadier, more significant rain Monday afternoon and Monday night. Exact temperatures on Monday depend upon whether that flow can try to turn around to more southerly ahead of the approaching low. It will be mild though for December. The low pressure from the west will advance eastward across the area Monday night then away to the northeast Tuesday.